What is the purpose of the valve cap on a gas cylinder?

The valve cap on a gas cylinder serves the primary purpose of protecting the cylinder valve from physical damage. Gas cylinders are often transported or stored in environments where they might be subject to impact, and the valve is one of the most vulnerable components. The cap provides a protective barrier that can absorb shocks or impacts, thereby ensuring that the valve remains intact and functional.

While the other options may mention aspects related to gas escape or weighing, the fundamental responsibility of the valve cap is to safeguard the integrity of the valve itself. When the cap is securely in place, it significantly reduces the risk of damage that could otherwise lead to leaks or operational failures. In summary, the valve cap is crucial for maintaining the safety and operational reliability of gas cylinders.